1. Field of the Invention
The present invention relates to a halogen-free flameproof mesh sheet used outdoors, such as at a construction site for a long time.
2. Description of the Related Art
In recent years, there has been a trend toward the construction of buildings having a large number of stories in the construction industry. Meanwhile, there has been an increase in the number of houses having a small number of stories. Flameproof mesh sheets for safety and protection, flameproof mesh sheets for houses having a small number of stories, and scattering prevention flameproof mesh sheets must be laid in these buildings and regulations are becoming more and more strict.
Currently used flameproof mesh sheets and scattering prevention flameproof mesh sheets are produced by weaving yarn prepared by coating a polyester, nylon, or polypropylene multi-filament fiber with a vinyl chloride-based paste resin composition and heating and then heating the obtained cloth; and by coating a fabric prepared by weaving and processing a multi-filament fiber with a vinyl chloride-based paste resin composition, heating and processing to a desired shape.
The resin composition for coating a fiber and fabric comprises a vinyl chloride resin containing chlorine as a resin and a chlorine-based flame retardant such as chlorinated paraffin, bromine-based flame retardant such as decabromodiphenyl oxide, or inorganic flame retardant such as antimony trioxide (See Examined Japanese Patent Publication Nos. 52-41786, 53-18065 and 61-9430, Plastics, February, 1991).
In recent years, it has been globally demanded to avoid the use of resins and flame retardants containing elemental halogen which generates harmful gas at the time of combustion from the viewpoint of the environmental preservation of the earth.
Japanese Laid-open Patent Application No. 61-223045 proposes that red phosphorus and ammonium phosphate are kneaded into a polyolefin to prevent corrosion by elemental halogen contained in an elemental halogen-containing compound flame retardant. However, there is unknown a flame retardant prepared by dispersing red phosphorus and ammonium phosphate in an aqueous dispersion of an ethylene-vinyl acetate-acrylate copolymer or an aqueous dispersion comprising the aqueous dispersion and an aqueous dispersion of an ethylene-based-.alpha.olefin copolymer and/or an aqueous dispersion of a polyurethane.
The inventor of the present invention has proposed in Japanese Laid-open Patent Application No. 9-225464 a halogen-free flame retardant comprising an aqueous dispersion of a polyolefin resin as a flame retardant. This flame retardant has an excellent effect, but there is seen a tendency toward an increase in the viscosity of the flame retardant due to time changes during storage.